1. Field of the Invention
The present invention relates to an antenna of the microstrip type for transmitting and receiving waves of wave-length .lambda. belonging to the frequency band ranging from 100 Mhz to 6 Ghz and presenting in particular excellent transmission and reception characteristics in the 3.5 Ghz bands, the C band and S band.
2. Description of Related Art
Microstrip antennas are well known. They are most often constituted by a first metallic plate forming a ground plane and by one or more other metallic plates disposed opposite the ground plane and which constitute radiator patches. These two metallic plate/patch systems are most often fixed on the opposite faces of a block of dielectric material, thus ensuring in addition the mechanical connection between the ground plane and the radiator patch or patches.
However, such a system may become expensive, in particular due to the cost of the high-quality dielectric material when the radiator patch or patches present a relatively large surface area.
To overcome this drawback, it has been proposed to use as dielectric the air located between the ground plane and the radiator patch. In the case of a single radiator patch, this solution is already very delicate to implement insofar as it is difficult to hold the radiator patch in a precise position with respect to the ground plane and to ensure a mechanical connection between these two plates which can withstand outside stresses. This problem is rendered even more complex in the case of the radiating part of the antenna having to comprise a plurality of metallic patches since the latter must be maintained strictly in the same plane.